patch-2.3.23 linux/mm/page_io.c

• Lines: 133
• Date: Tue Oct 19 10:22:19 1999
• Orig file: v2.3.22/linux/mm/page_io.c
• Orig date: Fri Oct 15 15:25:14 1999

diff -u --recursive --new-file v2.3.22/linux/mm/page_io.c linux/mm/page_io.c
@@ -33,7 +33,7 @@
  * that shared pages stay shared while being swapped.
  */
 
-static void rw_swap_page_base(int rw, unsigned long entry, struct page *page, int wait)
+static int rw_swap_page_base(int rw, pte_t entry, struct page *page, int wait)
 {
 	unsigned long type, offset;
 	struct swap_info_struct * p;
@@ -42,17 +42,10 @@
 	kdev_t dev = 0;
 	int block_size;
 
-#ifdef DEBUG_SWAP
-	printk ("DebugVM: %s_swap_page entry %08lx, page %p (count %d), %s\n",
-		(rw == READ) ? "read" : "write", 
-		entry, (char *) page_address(page), page_count(page),
-		wait ? "wait" : "nowait");
-#endif
-
 	type = SWP_TYPE(entry);
 	if (type >= nr_swapfiles) {
 		printk("Internal error: bad swap-device\n");
-		return;
+		return 0;
 	}
 
 	/* Don't allow too many pending pages in flight.. */
@@ -63,23 +56,16 @@
 	offset = SWP_OFFSET(entry);
 	if (offset >= p->max) {
 		printk("rw_swap_page: weirdness\n");
-		return;
+		return 0;
 	}
 	if (p->swap_map && !p->swap_map[offset]) {
-		printk(KERN_ERR "rw_swap_page: "
-			"Trying to %s unallocated swap (%08lx)\n", 
-			(rw == READ) ? "read" : "write", entry);
-		return;
+		pte_ERROR(entry);
+		return 0;
 	}
 	if (!(p->flags & SWP_USED)) {
 		printk(KERN_ERR "rw_swap_page: "
 			"Trying to swap to unused swap-device\n");
-		return;
-	}
-
-	if (!PageLocked(page)) {
-		printk(KERN_ERR "VM: swap page is unlocked\n");
-		return;
+		return 0;
 	}
 
 	if (rw == READ) {
@@ -104,13 +90,13 @@
 		for (i=0, j=0; j< PAGE_SIZE ; i++, j += block_size)
 			if (!(zones[i] = bmap(swapf,block++))) {
 				printk("rw_swap_page: bad swap file\n");
-				return;
+				return 0;
 			}
 		zones_used = i;
 		dev = swapf->i_dev;
 	} else {
 		printk(KERN_ERR "rw_swap_page: no swap file or device\n");
-		return;
+		return 0;
 	}
  	if (!wait) {
  		set_bit(PG_decr_after, &page->flags);
@@ -124,20 +110,15 @@
  	 * decrementing the page count, and unlocking the page in the
  	 * swap lock map - in the IO completion handler.
  	 */
- 	if (!wait) {
- 		return;
-	}
+ 	if (!wait)
+ 		return 1;
+
  	wait_on_page(page);
 	/* This shouldn't happen, but check to be sure. */
 	if (page_count(page) == 0)
 		printk(KERN_ERR "rw_swap_page: page unused while waiting!\n");
 
-#ifdef DEBUG_SWAP
-	printk ("DebugVM: %s_swap_page finished on page %p (count %d)\n",
-		(rw == READ) ? "read" : "write", 
-		(char *) page_address(page), 
-		page_count(page));
-#endif
+	return 1;
 }
 
 /*
@@ -149,7 +130,7 @@
  */
 void rw_swap_page(int rw, struct page *page, int wait)
 {
-	unsigned long entry = page->offset;
+	pte_t entry = get_pagecache_pte(page);
 
 	if (!PageLocked(page))
 		PAGE_BUG(page);
@@ -157,7 +138,8 @@
 		PAGE_BUG(page);
 	if (page->inode != &swapper_inode)
 		PAGE_BUG(page);
-	rw_swap_page_base(rw, entry, page, wait);
+	if (!rw_swap_page_base(rw, entry, page, wait))
+		UnlockPage(page);
 }
 
 /*
@@ -165,7 +147,7 @@
  * Therefore we can't use it.  Later when we can remove the need for the
  * lock map and we can reduce the number of functions exported.
  */
-void rw_swap_page_nolock(int rw, unsigned long entry, char *buf, int wait)
+void rw_swap_page_nolock(int rw, pte_t entry, char *buf, int wait)
 {
 	struct page *page = mem_map + MAP_NR(buf);
 	
@@ -173,5 +155,6 @@
 		PAGE_BUG(page);
 	if (PageSwapCache(page))
 		PAGE_BUG(page);
-	rw_swap_page_base(rw, entry, page, wait);
+	if (!rw_swap_page_base(rw, entry, page, wait))
+		UnlockPage(page);
 }